DENIERS SAY:

Many small islands are now higher above sea level than before.

SCIENCE SAYS:

The more sea levels rise, the more difficult it gets for low-lying islands to keep their heads above water.

Globally, sea levels are rising as the world warms. But look at a finer scale, and you’ll see that sea level rise varies a lot from place to place. Areas like coastal Louisiana are sinking for both natural and manmade reasons, so they’re experiencing higher-than-average rates of sea level rise. In a few places, like Kodiak Island, Alaska, the land is rising — meaning that sea level is actually falling slightly. Coral reef islands (mostly found in the South Pacific) show a similarly complicated pattern. Some of these low-lying islands have survived the changes in sea level rise so far. But others have disappeared entirely. What’s clear is that as the rate of sea level rise increases, it will be more and more difficult for coral reef islands — and the people who live on them — to keep their heads above water.

Additional info from the United States Global Change Research Program

Sea level rise will have enormous effects on many island nations, including the coral reef atolls found mostly in the South Pacific. Flooding will become more frequent due to higher storm tides, and coastal land will be permanently lost as the sea inundates low-lying areas and the shorelines erode. Loss of land will reduce freshwater supplies and affect living things in coastal ecosystems. For example, the Northwestern Hawaiian Islands, which are low-lying and therefore at great risk from increasing sea levels, have a high concentration of endangered and threatened species, some of which exist nowhere else. The loss of nesting and nursing habitat is expected to threaten the survival of already vulnerable species.

Hurricanes, typhoons, and other storm events, with their intense precipitation and storm surge, cause major impacts (PDF) to Pacific and Caribbean island communities, including loss of life, damage to infrastructure and property, and contamination of freshwater supplies. As the climate continues to warm, the peak wind intensities and near-storm precipitation from future tropical cyclones are likely to increase. This, combined with sea level rise, is expected to cause higher storm surge levels. If such events occur frequently, communities would face challenges in recovering between events, resulting in long-term deterioration of infrastructure, freshwater and agricultural resources, and other impacts.

Critical infrastructure, including homes, airports, and roads, tends to be located along the coast. Flooding related to sea-level rise and hurricanes and typhoons negatively affects port facilities and harbors, and causes closures of roads, airports, and bridges. Long-term infrastructure damage would affect social services such as disaster risk management, health care, education, management of freshwater resources, and economic activity in sectors such as tourism and agriculture.